摘要
光源掩膜协同优化是45 nm节点以下浸没式光刻提高分辨率的重要途径之一,为了重构其优化后输出的像素级光源,提出了一种基于可寻址二维微反射镜阵列的新型照明模式变换系统设计方法。分析了减少重构光源所需微反射镜数量的原理,结合成像与非成像光学,利用柱面复眼透镜,获得了入射到微反射镜阵列上的非均匀的特定光强分布,基于此光强分布对微及射镜二维偏转角度进行了模拟及优化,并对该照明模式变换系统进行仿真,结果表明,光瞳重构精度小于2.5%,X,Y方向光瞳极平衡性小于0.5%,Prolith中重构光源的曝光性能仿真结果满足要求。与类似的系统相比,该系统仅用不足4000个镜单元即可达到设计要求,适用于集成度高的下一代浸没式光刻系统。
Source and mask co-optimization is one of the most important resolution enhancement solutions in immersion lithography for nodes 45 nm and below. In order to reconstruct the optimum output pixelated source, a novel illumination mode conversion system design method based on a two-dimensional addressable micro-mirror array is proposed. The principle of reducing the number of micro-mirror required to reconstruct the source is analyzed, combing imaging and non-imaging optics, using cylindrical fly-eye lens to achieve the specific non- uniform intensity distribution on micro- mirror array. Based on this, optimization of each title angle of micro-mirror is programmed and the whole system is simulated. The results show the accuracy of the reconstructed source is less than 2.5 %, and pupil non-balance X, Y is below 0.5 %. The simulation results of reconstructed source with Prolith meets the design requirements. Compared with similar systems, the system ensures that the accuracy of reconstructed source with less than 4000 micro-mirror element, it＇s suitable for high integration of the next generation of immersion lithography system.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2015年第11期94-103,共10页
Acta Optica Sinica
基金
国家科技重大专项(2012ZX02701)
关键词
成像系统
照明模式变换
自由照明光瞳
微反射镜阵列
光束整形
非球面复眼
imaging systems
illumination mode conversion system
free-form pupil
micro-mirror array
beam shaping
aspheric cylindrical lens
